Deck loaded cargo can now be secured by spreaders extending across the upper rows of side-by-side cargo containers. Typically, these spreaders and/or equalizers grasp and firmly hold cargo in side-by-side relation once they are deposited on top of a group of containers.
It is desirable to remotely place such spreaders on top of a stack. Therefore, when such equalizer spreaders are grasped by a conventional lifting spreader, release from the cargo containers on which they have been placed is desired. Preferably, this release must be automated.
Heretofore, outwardly extending bars have accomplished these functions. When a spreader is placed on top of the bar, the bar reciprocates downwardly. Upon downward reciprocation, an eccentric imparts rotary motion to a shaft. The shaft in turn withdraws corner hooks from the side openings of castings. Thus when the equalizer spreader is grasped by a conventional loading spreader, detachment from the underlying containers on which the equalizer spreader has been placed, remotely occurs. The spreader may be lifted.
Unfortunately, such rods made to bias against the undersides of spreaders met with difficulty. Typically, since the spreaders are given what may at best be described rough treatment, their undersurfaces are often irregular. Frequently, they are bent and warped to a degree wherein predictable depression of the underlying bar cannot always be counted on.
Secondly, and due to the high speed function in which modern off-loading and on-loading occurs, there is oft times great relative motion between the relatively heavy spreader and the equalizer or load stabilizing spreader which is grasped. This being the case, the spreader oft times slams into the bar and produces bending. The bar once bent, renders the remote attachment features of the equalizer spreader inoperative. There results the need for costly repair.